require "git";

# open repo
repo = Git::Repo.open "./"
# get tree
tree = repo.head.to_commit.to_tree

entries = [] of Git::C::X_TreeEntry

cb = ->(x : Pointer(UInt8) , entry : Git::C::X_TreeEntry, entries: Pointer(Void)) do
  entries.as(Pointer(Array(Git::C::X_TreeEntry))).value << entry
  0
end

# walk tree and collect entries
Git::C.tree_walk(tree.safe, Git::C::TreewalkMode::TreewalkPre, cb, pointerof(entries))

objects = [] of {String, Git::Object}

# create Objects for entries in repo
entries.map do |entry|

  Git::C.tree_entry_to_object out ref, repo.safe, entry
  object = Git::Object.new repo, Git::Safe::Object.free(ref)
  name = String.new(Git::C.tree_entry_name entry)
  objects.push({ name, object })
end

#
# this fails with an invalid memory access
#
pp(
  objects.map do |(name, object)|
  s = object.safe.to_unsafe.as(Git::C::X_Blob)
  Git::C.blob_filtered_content out ref, s, "test.txt", 1
  end
)